The cells have a cylindrical shape with a broad elliptical cross-section. They are linked together in straight chains, featuring larger elliptical to hexagonal openings between the cells. The valves are flat to slightly concave and come with a short mantle and a small central process. Setae originate slightly inside the valve margin at the apical poles. They have a short basal portion and then join with those of the adjacent cell. The setae are quadrangular in cross-section and are adorned with tiny spines along the edges. Typically, the setae bend toward the nearest end of the chain. One part of the setae runs almost parallel to the apical axis, while the other part diverges significantly, nearly parallel to the transapical axis. Within the cells, numerous small chloroplasts are present, and these chloroplasts are also found within the robust setae.